The Black Tetra (Gymnocorymbus Ternetzi) is a beautifully marked little fish originated from Paraguay, which likes a temperature ranging from 700 to 800. Although it reaches a length of three inches in its native streams, it rarely grows to be more than two inches in watertanks. This is really just as well for the larger specimens are not nearly as clearly marked as the smaller ones. If you want to breed them you should put them in a separate watertanks with some of the floating plants, and with the bottom well planted with one of the “grassy” plants. After the egss have been laid on the plants we should take away the adult fish and then the eggs should hatch out in about three days. Being of peaceful disposition, the Black Tetra is an excellent fish for the community watertanks, and its habit of “schooling” makes it distinctive when there are two or more fishes in the same aquarium.